This invention relates to printers for printing indicia on labels and is particularly directed to label printers for printing on labels cost, weight and other information relating to purchased items, which information is provided by associated electronics and an electronic computing scale.
In the past, label printers have been provided for printing on a label weight and price information, for example, derived from an electronic computing scale which weighs a purchased item and calculates the cost of the weighed item. The electronic computing scale is interfaced with the printer so as to cause the printer to print the calculated information on a label.
Some such prior label printers require an undesirably large number of mechanical parts and are therefore costly and subject to wear and breakdown. In addition, such label printers frequently employ a label platen to support the label in alignment with a print head which prints the calculated information on the tape. In the past, such platens have been provided with means for adjusting their position with respect to the print head, but such adjusting means has been undesirably cumbersome and subject to need for readjustment.
Further, many prior label printers have been designed to use label tape having a bottom supporting layer which is removably attached to a top print-receptive layer. For such printers, additional and separate means have been provided (usually a rounded breaker bar) downstream of the platen, to cause separation of the top print receptive layer from the bottom supporting layer. Such separate means then require additional separate and difficult adjustment to maintain an effective spacial and functional relationship with the platen and the print head.
After the print-receptive layer has been imprinted, the bottom supporting layer is detached from the top print-receptive layer and is collected on a take-up spool. When a large amount of the bottom supporting layer has been collected on the take-up spool, it can be difficult to readily remove the collected bottom layer from the take-up spool because of the tightness with which the bottom layer is wound.
An additional problem associated with prior label printers is that their label advancement mechanism, including rollers, sprocket wheels and the like, interferes with the initial manual threading of the label tape through the tape advancement mechanism. This and the above-mentioned problems with prior label printers have made their use and adjustment for use more difficult than is desirable.
Accordingly, it is an object of this invention to provide an improved label printer which avoids the above-described deficiencies associated with prior label printers.
It is a more specific object of this invention to provide a label printer of simple mechanical construction and having a readily adjustable platen.
It is another object of this invention to provide a label printer having a take-up spool adapted for easy removal of collected tape therefrom.
It is yet another object of this invention to provide a label printer whose housing and label advancement mechanism permit easy manual threading of the label tape through the label advancement mechanism.